Eye Diagram Measurements - Rohde & Schwarz RTE1022 User Manual

®
R&S RTE
a) On the "Measurements Setup" tab, select "Delay to trigger" as main or addi-
b) Select the source, that is the waveform with the delayed slope to be measured.
c) Select the slope, and the reference level
d) Check the trigger settings.
e) Enable the measurement and note the result.
3. Turn the horizontal POSITION / REF POINT knob and enter the measured delay
as horizontal position.
Thus, the slope is moved to the center of the screen.
4. Adjust the horizontal scale and the horizontal resolution parameters (RES REC
LEN) to the required accuracy: "Sample rate", "Resolution", or "Acquisition time".
The trigger is outside the display and is not part of the current acquisition.
5. Repeat the "Delay to trigger" measurement.
Now the delay is measured with high accuracy. You can analyze the variance of
delay values using statistical evaluation and histogram functions.

7.2.6 Eye Diagram Measurements

The eye diagram is a superposition of repetively sampled digital data. It is a tool for
evaluation of signal quality and shows the combined effects of channel noise and inter-
symbol interference. The eye diagram is a significant means of visualizing jitter and
allows you to analyze the reasons for it. By creating histograms of the eye diagram,
important jitter parameters can be determined.
The waveform display style must be set to vectors: DISPLAY > "Signal Colors / Persis-
tence" tab > "Style = Vectors"
The following characteristic values can be determined:
Vcrossing
Figure 7-7: Basic eye diagram characteristics
User Manual 1326.1032.02 ─ 11
tional measurement.
3σcrossing1 Eye width
Tcrossing1
Automatic Measurements
3σcrossing2
Tcrossing2
Measurements
Eye top
Eye base
308